They really cared about that piece of intellectual property too. Anecdote time: Back in the early 00’s I was part of a small team developing a mobile phone for Docomo (using Openwave’s framework). Bug came back saying Docomo emojis are the wrong color. To which we replied, tell us the color codes and we’ll fix it. The reply was, we cannot - because Docomo emoji colors are secret. Those were good times! :)

https://stories.moma.org/the-original-emoji-set-has-been-add...

List of original emojis

This sounds like an interesting piece of Japanese culture about which I knew nothing. Anyone have more background?